1. Field of the Invention
The present invention relates to a compound or derivatives of gabapentin, especially a compound or derivatives of gabapentin for medical purposes.
2. Description of Related Art
Gabapentin is used widely in the treatment of epilepsy and in pain syndrome therapy and in 2001; its global sales reached US$1.47 billion. However, the drug has poor oral bioavailability, and 900 to 4800 mg in dosage for three times per day is required to approach the desired efficacy. However, it was found that the greater dosage in administration did not result in relative adsorption enhancement. Moreover, the change of the administration method did not increase the oral bioavailability. Therefore, according to the prodrug concepts, if the gabapentin can be designed as a highly bioavailable prodrug to reduce the dosage amount and regime such that it need be taken only one time per day, then the convenience for the patients will be largely promoted.
Previously, the cyclic amino acid (gabaperitin) was used to conjugate with the twenty natural amino acids to produce its derivatives and increase its standing time in the body. The related art is achieved by chemical synthesis, which describes the synthesis pathway, yet the related tests were not extended to prove the efficacy of the designed derivative.